BRT rapid transit signal priority control intelligent management system
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1 Introduction
1.1 Document construction instructions
The purpose of this program is to let integrators, engineers and users understand the design concepts, principles, overall planning and how to play a huge role in the field of intelligent transportation of the Internet of Things RFID technology, and elaborate on the working principles and installation locations of related Internet of Things equipment. Information so that integrators, engineers, and users can correctly understand the revolutionary changes brought about by the Internet of Things in the field of intelligent transportation, and establish a correct understanding of the Internet of Things in the field of intelligent transportation. If you encounter any confusion or confusion during the reading process, please contact the program writer.
1.2 Explanation of terms and abbreviations
Term explanation
2. Project background
2.1 Status analysis
As a new type of passenger transportation mode, the BRT system is considered to be one of the effective ways to solve the problem of urban traffic congestion due to its advantages of low project investment, short construction period, low environmental pollution, and high transportation efficiency. Successfully promoted and applied. Under the strong influence of the construction of rapid transit systems in many cities in the world and the strong promotion of relevant policies in my country, the domestic transportation industry and major cities have begun to push the rapid transit system to the forefront of alleviating urban traffic pressure. In the next 5 years, there will be 10 in China. The above cities have built a rapid transit system, which is expected to have a total length of 300 to 500 kilometers and a daily passenger flow of 2 to 4 million;
Public transportation is an important means to improve the efficiency of transportation resource utilization and alleviate traffic congestion, and it is the main direction of solving traffic problems in big cities. With the expansion of the scale of the city and the development of the economic level, the needs of urban residents to improve travel conditions, especially the convenience of public transportation, are becoming more and more urgent;
Under this background, Ren Microelectronics has vigorously developed the Internet of Things technology to improve my country’s urban public transport construction level and improve service quality, and developed an intelligent management system for the priority control of BRT signals based on RFID technology;
2.2 Significance of system construction
1. Reduce the travel time of public lines and reduce the delay of public vehicle intersections;
2. Reduce the number of parking of public vehicles, improve the stability and accuracy of public vehicles, and improve the level of public transport services;
3. Reduce the delay of social vehicles on the main line and the length of the line of vehicles;
4. Reduce vehicle energy consumption, manpower and transportation equipment;
3. System Overview
3.1 System design principles
The system development and construction follow the following principles:
Focus on overall planning
The BRT signal priority control intelligent management system consists of three parts. First, the core hardware of the BRT signal priority control system (including: 2.4G active electronic tags, directional readers). Second, the BRT signal priority control system platform (Including intersection control subsystem, signal communication subsystem, intelligent traffic control); third, hardware middleware (including signal control machines, industrial-grade switches, cabinets, PCs, servers, uninterruptible power supplies, etc.);
Based on independent research and development
The core technology of the system construction adopts the standard 2.4G active microwave frequency band commonly used in the market. All the core equipment provided by the company has completely independent intellectual property rights, 2.4G micro-power technology, automatic identification of long-distance moving vehicles and non-contact information Collection and processing, the advanced information technology, data communication technology, electronic control technology and computer processing technology are effectively and comprehensively applied to the ground transportation management system, thus establishing a large-scale, all-round function, and real-time, accurate and efficient Traffic management system. To achieve the purpose of prioritizing public transport signals;
Focus on future development
In terms of the overall system architecture, service equipment selection, active electronic label function selection, basic data collection, etc., full consideration is given to the realization of subsequent functions, taking into account the compatibility of equipment, system scalability, function scalability and application Diversity;
Strengthen system specifications
System development and resource construction conform to a unified technical specification and characterization system, pay attention to the continuity and sharing of development work, and pay attention to leaving standardized data and control interfaces for subsequent system development and promotion. Unified development of technical indicators such as application technology, data storage format, signal transmission system, and interconnection interface mode;
Utilize construction benefits
The development and construction of the system should combine the actual conditions of the traffic area, and further strengthen the management of the traffic on the basis of the existing system; follow the overall planning, construction while using, and gradually improve the construction ideas to give full play to the construction benefits;
3.2 The working principle of the system
The BRT signal priority control intelligent management system refers to the priority given by the traffic signal system to BRT vehicles in terms of “time”, which is mainly reflected in: when the BRT vehicle drives near the intersection, the traffic signal system recognizes the vehicle and judges the vehicle’s status The direction of operation provides a priority signal for the bus.
The BRT signal priority control intelligent management system mainly includes active electronic tags and base station type directional readers. Its basic working principle and characteristics are that when the RFID base station type directional reader detects that the BRT vehicle is approaching an intersection, it sends a request signal to the intersection signal, and the RFID base station type directional reader recognizes the detected BRT vehicle. , And transmit the information to the traffic signal control system in real time through the dedicated communication optical fiber, and the traffic control system center will issue instructions to the intersection signal machine for timing adjustment. The traffic control system of BRT vehicles adopts two solutions: (1) When the BRT vehicle approaches the intersection and encounters a green light, the current green light phase time is appropriately extended by 8 seconds to ensure that the BRT vehicle passes through the intersection smoothly; (2) When the BRT vehicle approaches the intersection When the intersection encounters a red light, shorten the red signal cycle and switch to the green light phase of the BRT vehicle driving 8 seconds in advance, thereby reducing the delay time of the BRT vehicle at the intersection;
3.3 Schematic diagram of overall system design
3.4 System function introduction
When the vehicle arrives at the intersection, the RFID reader reads the tag and obtains vehicle information; obtains the real-time scheduling status of the vehicle by interacting with the intelligent scheduling system, including whether it is late, whether it is express scheduling, and the full load rate, etc., and generates a request according to the real-time status of the vehicle; After that, the signal priority system submits a priority application to the traffic management department. The traffic management department system processes the request based on the original plan information and real-time scheduling information, and finally gives priority results; after the vehicle leaves the positioning area, the signal control system enters The signal state is restored to the state, until the signal state is restored, the signal priority scheduling process is completed;
3.5 System software introduction
Traffic signal control system
The traffic signal control system is an important subsystem of the intelligent traffic management system, and it plays a role of the nerve center in constructing the intelligent management system of the BRT signal priority control. When the RFID base station type directional reader detects the identity of the BRT vehicle, and transmits the information to the traffic signal control system in real time through the dedicated communication optical fiber, the traffic control system center then issues instructions to the intersection signal machine for timing adjustment;
4. Overall system construction plan
The design of the intelligent management system for the BRT signal priority control includes the intelligent bus dispatching system and the BRT vehicle signal priority control system. The two parts are independent and closely related to each other, and jointly form the intelligent and information management of the transportation field;
Below we explain in detail the two components of the intelligent management system for the priority control of the BRT signal.
4.1 BRT vehicle signal priority control system
The RFID base station type directional reader is installed at 100-200 meters away from the intersection. When the bus approaches the intersection, the 2.4G active electronic tag on the front of the car echoes the RFID base station type directional reader installed on the roadside, reading and writing When the signal is connected with the traffic signal control system of the traffic command center, the traffic signal lights at the intersection will change: extend the green light in the direction of the dedicated lane for BRT vehicles, or shorten the red light;
4.1.1 Hardware composition
1) RFID base station type directional reader, RFID base station type directional reader is installed 100-200 meters away from the intersection, used to read active electronic tag information on BRT vehicles, and output through serial port 485 or RJ45, relay, Connect with the traffic command center and the traffic signal control system for signal transmission and communication;
2) RFID active radio frequency card, installed in each controlled BRT vehicle, for vehicle information identification;
3) The traffic signal control machine adjusts the timing of the traffic signal so that the green light is delayed and the red light is advanced;
4.1.2 Precautions for hardware installation
1) RFID base station type directional reader, please pay attention to the installation position, height, waterproof connector (power connector, network connector), and the installation angle of the antenna panel;
2) The installation position of the RFID active radio frequency card on the BRT vehicle can be bundled or hung, and pasted on the front windshield of the vehicle or the rearview mirror of the vehicle;
3) The installation of optical fiber communication system mainly pay attention to the waterproof of the connector;
4.2 Schematic diagram of the overall architecture of the intelligent bus dispatching system
Through the traffic control system, the traffic management department processes the priority signals sent by the BRT vehicles on the basis of the original driving plan and labor scheduling, and at the same time, according to the real-time scheduling status of the BRT vehicles, including whether it is late, whether it is express scheduling, full load rate, etc. Situation, generate request;
4.2.1 System hardware composition
1) RFID base station type directional reader, please pay attention to the installation position, height, waterproof connector (power connector, network connector), and the installation angle of the antenna panel;
2) The installation position of the RFID active radio frequency card on the BRT vehicle can be bundled or hung, and pasted on the front windshield of the vehicle or the rearview mirror of the vehicle;
3) The installation of optical fiber communication system mainly pay attention to the waterproof of the connector;
4.2.2 Precautions for system hardware installation
1) RFID base station type directional reader, please pay attention to the installation position, height, waterproof connector (power connector, network connector), and the installation angle of the antenna panel;
2) The installation position of the RFID active radio frequency card on the BRT vehicle can be bundled or hung, and pasted on the front windshield of the vehicle or the rearview mirror of the vehicle;
3) The installation of optical fiber communication system mainly pay attention to the waterproof of the connector;
5. Introduction of hardware equipment
5.1 RW-R901 base station type directional reader
Product technical characteristics
Recognition distance: 0 ~ 150 meters
Recognition speed: 200 km/h
Recognition ability: Recognize more than 500 labels at the same time
Recognition angle: Orientation (30° vertical and 30° horizontal)
Polarization mode: circular polarization (more suitable for applications where the label orientation is changeable)
Gain: 16dBi, 32 levels adjustable for receiving, 4 levels adjustable for transmitting
Working frequency band: 2.4 GHz ~ 2.4835 GHz
Power consumption standard: working power is milliwatt
Communication mechanism: Based on HDLC time division multiple access and synchronous communication mechanism
Anti-interference: channel isolation technology, multiple devices do not interfere with each other
Security: Encrypted calculation and security authentication to prevent link detection
Interface standard: RS232, RS485, Wiegand26, RJ45, TTL, WiFi, etc. optional
Expansion I/O: 2 channels of switch signal input and output (optional)
Power standard: DC 7.5～12V 500～1000mA
Packaging features: ABS engineering plastic on the front, aluminum alloy cavity on the back
Reliability: Thunderproof, waterproof and shockproof, meeting the requirements of industrial environment
Size: 268×268×80mm
Weight: 2.1kg
Installation method: U-shaped special metal installation kit
5.2 RW-T901 type small electronic label
Product technical characteristics
Recognition distance: 0～150 meters adjustable
Recognition speed: 200 km/h
Recognition ability: 200 frames per second anti-collision performance
Recognition method: omnidirectional recognition
Fixed gain: 0～3 levels can be selected on demand
Working frequency band: 2.4 GHz ~ 2.4835GHz
Communication rate: 250Kb/s, 1Mb/s, 2Mb/s
Communication mechanism: Based on HDLC time division multiple access and synchronous communication mechanism
Anti-interference: channel isolation technology, multiple devices do not interfere with each other
Security: Encrypted calculation and security authentication to prevent link detection
Read and write function: 176B storage space (optional)
Anti-dismantling function: Anti-dismantling alarm function (optional)
Temperature measurement function: temperature measurement accuracy ±0.4° (optional)
Power consumption standard: The average working power is microwatts
Battery configuration: button type lithium manganese battery, capacity 500mAh
Service life: about 2 to 3 years, replaceable battery
Voltage detection: wireless prompt when the voltage is lower than the preset value (optional)
Packaging characteristics: ABS engineering plastic, resistant to high-strength drops and vibration
Environmental characteristics: Working temperature -40℃ ～85℃
Working humidity<95%
Reliability: Waterproof and shockproof, meeting the requirements of industrial environment
Appearance: Square card type, OEM customized service can be provided
Size: 65×34×7 mm
Weight: 18g
Installation method: double-sided adhesive paste or hanging buckle
6. Project implementation
6.1 Project implementation process
Project implementation process
6.2 Project after-sales service
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